The modern communications era has brought about a tremendous expansion of communication networks. Communication service providers (e.g., wireless, cellular, internet, etc.) and device manufacturers are continually challenged to deliver value and convenience to consumers by, for example, providing compelling network services, applications and contents. One area of interest has been the development of social networking services and other services for making connections and communicating data, contents or resources among users. One exemplary service is that user equipments such as personal mobile devices (e.g., smart phones) can be self-organized and communicate with each other for social activities, for example by forming a multi-hop radio network, and maintaining connectivity in a decentralized manner. Such kind of social networking based on mobile devices that supports instant and pervasive social activities can be called as pervasive social networking (PSN).
It is crucial to ensure the security of the communication, for example to avoid malicious eavesdropping. However, it is difficult to provide a secure communication in a distributed manner, in which situations there is no centralized server, for example in a distributed communication network. Moreover, in some situations (e.g., disasters, military activities), it is hard to connect to a centralized server. Thus, a secure communication and access control solution based on a traditional centralized server may not be applicable for the distributed communication in some situations. Thus, service providers and device manufacturers face significant technical challenges to provide secure communications in a distributed manner.